The approaches described in this section could be pursued, but are not necessarily approaches that have been previously conceived or pursued. Therefore, unless otherwise indicated herein, these approaches are not known to be prior art and are not admitted to be prior art by inclusion in this section.
Automated gesture recognition has been the subject of considerable study since 1995. One objective of gesture recognition was control of machines, as described in U.S. Pat. No. 5,594,469 to Freeman et al., entitled “Hand Gesture Machine Control System.” The approach used by Freeman et al. was to have a hand gesture in space cause movement of an on-screen displayed hand icon over an on-screen displayed machine control icon. The hand icon moved the machine control icon to effectuate machine control.
In U.S. Pat. No. 6,002,808 to Freeman, entitled “Hand Gesture Control System,” hand gestures are sensed optically through use of a camera, and converted into a digital representation based on horizontal and vertical position of the hand, length and width of the hand, and orientation of the hand.
In U.S. Pat. No. 7,058,204 to Hildreth et al., entitled “Multiple Camera Control System,” a multi-camera technology is described, whereby a person can control a screen by pointing a finger.
More recent studies have included controlling a man-machine interface by tracking where a user is viewing a display device. For example, U.S. Pat. No. 6,373,961 to Richardson et al., entitled “Eye Controllable Screen Pointer,” discloses a system that tracks eye movements to control a screen pointer.
Gesture and eye based control of man-machine interfaces has many advantages over various physical interfaces, such as a touch screen displays, switches, mouse devices, keypads, and keyboards for controlling electronic systems. Physical interfaces need to be positioned within the convenient reach of a person. When physical interfaces are intended for use in a public setting, problems can arise in that the physical interface surfaces may become unsanitary or unattractive to users. Moreover, physical interface surfaces are subject to wear, which can diminish their useful life and increase maintenance costs. Furthermore, there is the potential for abuse and damage from vandalism to physical interfaces.